1. Technical Field
A semiconductor memory device is disclosed in which defective cells caused due to a minute leakage current on bit lines and complementary bit lines can be screened.
2. Discussion of Related Art
In semiconductor memory devices such as DRAMs, defects are generated in cells of a memory block due to a minute leakage current on unspecific bit lines and complementary bit lines due to process defects. Accordingly, these defects need to be screened. A time of several hundred microsecond to several millisecond is needed per one word line in order to screen these defects.
In the prior art, by activating one word line at a time, memory cells of all word lines are sequentially tested. Therefore, a significantly large amount of time is consumed to screen for weak cells. This causes the production costs to increase.